A so-called hybrid vehicle is kn that includes a plurality of power sources, for example, a prime mover such as an engine and an electric motor such as a motor. For example, a vehicle disclosed in Patent Document 1 is the hybrid vehicle. In such a hybrid vehicle, regenerative control is performed during deceleration etc., of the vehicle to convert a kinetic energy of the vehicle into an electric energy.
On the other hand, in a stepped shifting mechanism such as an automatic transmission, the gear ratio thereof is changed i.e., a shift is performed such that the prime mover can be operated in an efficient range depending on a traveling state of the vehicle.